Feeding device for combustion chambers



@c 8, M46., f R. H. GODDARD 2,409,036

FEEDING DEVICE FOR COMBUSTION CHAMBERS Filed OCL.' l2, 1942 Patented Oct. 8, 194i@ FEEDING DEVICE FOR COMBUSTION y CHAMB ERS Robert H. Goddard, Roswell, N. Mex., assignerv of one-halfA to The.v Daniel andFlorence Guggenheim Foundation, New York, N. Y., a corporation of NewYork Application October-:12, 1942, SerialNo. 461,670l

Claims. l

This invention relates to feeding devices particularly adapted for use in rocket motors in whichdischarge gases are continuously produced in a combustion chamber and are continuously ejected through a rearwardly directed nozzle,

lThe operating conditions in such rocket motors are very different from those encountered in oil-burning or gas-burning furnaces. In such furnaces, the combustion space is relatively large and the rate of fuel feed is relatively slow. In a rocket motor, most commonly used in aircraft, it is necessary to avoid excessive weight and the motor must be relatively small, with a combustion chamber of limited capacity and to which fuel and an oxidizing agent are fed at a rapid rate.

In order to secure a large power output from such a, relatively small power unit, it is desirable to use a mixture of. gasoline or other liquid fuel and a liquid oxidizing agent such, as liquid oxygen, but a mixture of such liquids is very explosive, and the ignition of any considerable amount of such a mixture produces violent and dangerous combustion.

It is the general object of my present invention to provide effective combustion for such a mixture of gasoline and liquid oxygen and also to reduce the violence of the combustion reac-A tion Without reducing the power output of the apparatus. I also maintain substantially continuous. discharge of combustion gases from the discharge nozzle.

To the accomplishment of these objects, I provide means for rapidly and periodically varying the feed of one or both liquids to they combustion chamber, so that combustion takes place in a rapid succession of relatively small explosions, with the combustion gases produced in a series of closely successive waves. These waves follow each other so rapidly that they intermingle in the combustion chamber and produce a substantially continuous and uniform flow of combustion gases through the discharge nozzle.

A more specific object of my inventionl is to provide means for periodically interrupting. the flow of each liquid and for more effectively mixing the gasoline and liquid oxygen. I also provide means for independently varying the intervals between feeding occurrences for each liquid.

My invention further relates to arrangements and combinations of parts which will be hereinafter described and more particularly pointed out in the appended claims.

Preferred forms of the invention are shown in the drawing, in which Fig. 1 is a sectional front elevationcff apreferred construction of feeding mechanism;

Fig. 2 is a partial perspective View of an annular stationary member formingpart. of thel mechanism shown in Fig. l

Fig. 3 is a. similar view of an annular rotating member used in the preferred construction.;

Fig. 4 is .a partial perspective View similar to Fig. 2 but showing a modificationto be described; and

Fig. 5 is a diagrammatic view illustratingv the shiftingl of the locus of impact of the two liquids under certain operating conditions.

In Figs. 1 to 3 I have shown a modified construction in which concentric and stationary annular' casing members 60- and 8! are fixed in the upper end portion 62A of the combustion chamber of a rocket motor. A feed pipe 63 for liquidoxygen is connected to the fixed outer casing 68, and a feed pipe 84 for liquid `fuel is connected to the fixed inner casing lil. At their lower-ends, thecasings 68 and 8l are-beveled at their inner and outer edges, as indicated at 85. and. Bin Fig. 2 and at 6l and 88 in Fig. l.

The beveled inner surface 85 of the fixed outer casing 68 is provided with a series of elongated circumferential slots 18, preferably arranged in staggered relation as best shown in Fig. 2. The beveled outer surface 88 of the fixed inner casing 6| is provided with aV similar series of slots 'Il (Fig. l).

A rotating annular member 'l5 is mounted within the outer fixed annular casing 64), anda corresponding. rotating annular member 16- is mounted within the inner fixed annular casingl.

The rotating annular member 'l5 is mounted at its upper end on balls 'i8 on a fixed ball race'y 7.9,/ and at its lower end said member is provided with beveled inner and outerv edge surfaces 88 and 8| (Fig. 3), slidably engaging the corresponding.. surfacesl 65- and 66 of the associated fixed annular casing 88. The inner surface is provided with` a series of staggered slots 82, arranged to coact with the slots 18.

The rotating annular member 15 is of similar construction and, is similarly mounted on balls 8% on a fixed ball race 85 in the fixed casingiil. Similar beveled surfaces are provided at the lower end of the rotating member 16, and one of these surfaces has staggered slots 88. It will be noted that the slots 10 and 82 of the coacting annular members 80 and 15 are directed inward, While the slots 1l and 88 of the coacting members 6l and 16 are directed outward.

The rotating annular member 15 has a rotor ring 90 (Fig. 1) of copper or aluminum, coacting with a. stator 9| to form an induction motor, and the inner rotating annular member 16 has a. similar rotor ring 92 coacting with a stator 93.

As the movable slots are rotated and intermittently brought into alignment; with the fixed slots, jets or slugs of liquid fuel and liquid oxygen will be fed to the combustion chamber along intersecting paths as indicated in Fig. 1, so that an intimate mixture of the two liquids is quickly attained. This construction has the advantage of delivering both liquids from extended coaxial annular passages and in opposite directions, thus providing a very thoroughly intermingled combustion mixture.

Different explosive effects may be obtained by varying the relative speed of the rotating annular members 'l5 and 16, which varying speeds may be attained by varying the frequencies of the induction motors.

In Fig. 4 I have shown a portion of an annular casing lill*i having slots 'l0a arranged in a somewhat different and less staggered relation. With this construction and with a similar arrangement of slots in the associated rotating member, the feed will be more definitely intermittent while the arrangement previously described shifts the admission area up and down between the upper and lower rows of slots.

All forms of my invention as above described thus provide very simple and effective means for periodically feeding liquids to a combustion chamber in separated portions, so that the combustion, while substantially continuous, nevertheless takes place at slightly spaced intervals. The intervals are, however, too short to completely extinguish the flame. Dangerous explosions of large amounts of the combustion mixture are thus avoided.

By changing the relative locations of the admission slots in the construction shown in Fig. 1 and as illustrated in Figs. 2 and 4, both the admission timing and the admission locus may be varied. By varying the frequencies, further variations in feed and proportionate mixture may be obtained.

'I'he change in locus of admission and impact of the two liquids, when using the stationary annular casing (il)a (Fig. 4) with the rotating member l5 and a corresponding stationary casing 6|a with the inner rotating member 16, is illustrated diagrammatically in Fig. 5.

It is assumed that the stationary casings and rotating members are so disposed angularly that a lower slot 'llla in the casing Sl'la will be opened simultaneously with an upper slot 1 Ib in the casing Sla, and that an upper slot b in the casing 60a will :be opened simultaneously with a lower slot 'Ha in the casing 6in.

With the slot Illa and Ilb open, the impact of the jets or sprays will occur at the locus X, while with the slots 10b and 'Ha open, the impact will occur at the locus Y. As one pair of slots is gradually closed and the other pair of slots is simultaneously and gradually opened, the locus of impact will shift back and forth between X and Y, but the net open slot area will remain approximately the same and the flow through the pipes 63 and 64 will be substantially uniform.

It is desirable that the frequency of the m0- tors be such as to produce periodic waves corresponding to'the dimensions of the combustion chamber. These waves may travel either longitudinally of the chamber or may expand toward the cylindrical chamber wall.

It will be understood that my improved feeding mechanism, while particularly designed for use with liquids, also possesses similar utility when used with gases.

Having thus described my invention and the advantages thereof, I do not wish to .be limited to the details herein disclosed, otherwise than as set forth in the claims, but what I claim is:

l. .Feeding mechanism for a combustion chamber in a rocket motor comprising separate means to feed liquid fuel and a liquid oxidizing agent to said chamber, and means to quickly and successively interrupt the feed of :both of said liquids as they enter said chamber and to simultaneously shift the locus of delivery of said liquids.

2. Feeding mechanism for a `combustion chamber in a rocket motor comprising concentric fixed annular casings mounted on said combustion chamber and projecting therein and having slots in their lower end portions, means to feed fluid fuel and a fluid oxidizing agent to said concentric fixed casings, rotatable annular members mounted within said fixed casings and having slots in their lower end portions coacting with said firstnamed slots to provide fluid passages when aligned therewith, and means to rotate said annular members.

3. The combination in a feeding mechanism as set forth in claim 2, in which the fluid passages of the outer pair of xed and rotating annular members are directed toward the axis of said rotating members and the fluid passages in the inner pair of fixed and rotating annular members are directed away from said axis.

4. Feeding mechanism for a combustion chamber in a rocket motor comprising concentric fixed annular casings mounted on said combustion chamber and projecting therein and having slots in their lower end portions, means to feed fluid fuel and a fluid oxidizing agent to said concentric fixed casings, rotatable annular members mounted within said fixed casings and having slots in their lower end portions coacting with said firstnamed slots to provide fluid passages when aligned therewith, and each rotatable member having a ring of conductive metal and constituting the rotor of an induction motor by which said member is rotated.

5. Feeding mechanism for a combustion chamber in a rocket motor comprising separate means to feed liquid fuel and a liquid oxidizing agent to said chamber, and rapidly rotated valve elements effective to shift the locus of delivery of both of said liquids to said chamber and of impact of said liquids Within said chamber successively and repeatedly during each rotation of said elements.

ROBERT H. GODDARD. 

